SIMBAD references

Recent analyses of Cepheid distances to spiral galaxies have led to the announcement of a Hubble constant of H₀=72±8 km.s^–1.Mpc^–1. The new Cepheid distances, however, show that there are numerous redshift distances with large excesses that cannot be due to peculiar velocities. Ignoring these discordant redshifts, if the Hubble constant is calibrated with Cepheid distances of low-redshift spirals, then a value near H₀=55 is obtained. Use of independent distance criteria such as Tully-Fisher and group membership verifies this value and leads to three conclusions: (1) the peculiar velocities of galaxies in space are characteristically small; (2) Sc companions to normal Sb galaxies tend to be less luminous, with younger stellar populations and small amounts of nonvelocity redshift; and (3) ScI and other purportedly overluminous spiral galaxies have large amounts of intrinsic redshift.